Metal Casting Vs. Metal Forging

“Metal forging vs. metal casting: which is better?” This question has been one of the most debated when it comes to rigging products. To get a more comprehensive answer, you will have to look deeper into each process.

Casting and forging are two different methods of fabricated metal parts. The two techniques have been used for ages. However, they are different in many ways.

For instance, while metal casting is always considered the best method for producing a wide variety of metal parts, forging may also be applicable, depending on your needs. You will find out more in this article.

What is Metal Casting?

The metal casting process involves the pouring of molten metal into molds or dies and allowing it to solidify and take the shape of the mold. This process is most suitable for the production of large volumes of metal components since the mold can be reused to create another identical product.

Accordingly, there are many types of metal casting. For instance, die casting involves the use of dies instead of molds. The molten metal is poured into the die and left to cool and solidify. Pressure is applied to the molten metal to harden it as it cools. The die casting process is widely used for high-speed applications.

Investment casting is another metal casting process. During this process, molten metal is poured into molds made of a ceramic slurry. The metal is left to cool and solidify before it is removed from the mold. In precision casting, the finished part always comes with an excellent surface finish that may not require post-processes. Investment casting is also known as lost foam casting or low wax casting.

Centrifugal casting is another casting process. This process differs from others since the mold used here is always rotating on a vertical or horizontal axis. This process is mainly suitable for manufacturing metal components with a constant diameter and thin walls.

The last metal casting technique is sand casting. The sand casting process involves the use of molds made from sand impacted with clay or any other binding material. This process may be time-consuming but generally more economical than other metal casting processes.

What is Metal Forging?

The metal forging process is a technique used to produce metal parts using compressive force. A hammer or die may be used to apply force on the metal to achieve the desired shape. When the metal is stricken, it is shaped and deformed. This also allows the metal to retain its strength since the grain and structure are not broken.

The grain flow means that the finished part comes with no defects, inclusions, and porosity. Accordingly, metal forging is relatively low cost. Once you assemble all the forging tools, you can produce many metal parts at a relatively high speed.

Metal forging can be done at room temperature. This process is always referred to as cold forging.  Accordingly, metal forging can be done where the metal is heated in a process called warm forging.

What Is the Difference between Metal Casting and Metal Forging?

Metal casting and metal forging are two different metal fabrication processes. To know more about their differences, you may want to look at them separately.

When Should You Use Metal Casting?

The metal casting process is mainly suitable for fabricating a wide range of metal components with complex shapes and forms. Accordingly, you may want to use casting (investment casting) if you want an excellent surface finish.

Additionally, metal casting does not require more energy. This means that when you have to produce a large volume of metal parts, you should use casting.

What Are The Advantages Of Casting?

• Casting can be used to produce metal parts of different sizes without limitations.
• The metal casting process uses a wide range of metals and alloys.
• Tooling is relatively less costly in metal casting than forging.
• The process requires smaller production runs.
• The metal casting process can be used to fabricate parts with intricate designs and shapes.

What Are The Disadvantages Of Metal Casting?

• Metal components made from casting are more porous with questionable structural integrity.
• Die casting is more expensive due to the tools used. Other casting methods may vary in costs.
• The metal casting processrequires constant monitoring and inspections to ensure quality and avoid defects.

Casting is mainly suitable for general GET and parts with intricate shapes.

When Should You Use Metal Forging?

Metal forging is suitable if you want uniformity in the part’s structure and composition. This aspect is because forging leads to metallurgical recrystallization and grain refinement. This happens when the metal piece is hit using a hammer or die. The resulting product often comes with high strength.

Forged products are generally more robust and reliable than cast products.

What Are The Advantages of Metal Forging?

• Forged parts have higher mechanical properties.
• Forged parts can handle impact better the cast components.
• Forging offers a continuous grain flow for structural refinement.
• The metal forging process eliminates porosity, shrinkage, and cold pour problems.
• Forging can be more affordable in some cases.
• Forged parts have excellent resistance to wear due to continuous grain low.

What Are The Disadvantages of Metal Forging?

• Forged products may not possess high tolerance levels.
• Many forged components require secondary processes to refine the finished part.
• Forged components are limited in shape and size.

How to Choose Between Metal Casting and Metal Forging

There are many factors to consider when choosing between forging and casting. Generally, you will want to treat every application differently and look for the most suitable method of metal fabrication. Below are some factors that should help you make a decision:

• Type of metal
• The final strength of the finished part
• Tolerance level
• Surface finish
• Sensitivity to temperature
• Net waste

Final Thoughts

When fabricating metal parts, there is no one fits all technique. You have to treat every project differently. Depending on the metal parts you want to manufacture, you can either choose forging or casting. These two processes have advantages and disadvantages that make them suitable for specific applications.